Despite forty years of evolution, rap music is still largely reluctant to adopt live instruments (unless, of course, you’re The Roots). Theoretics is an instrumental quintet clearly capable of holding its own in the rap arena. In July, the group dropped the first installment of its “One a Month” series, for which it will release a new collaboration with a local MC every month. The first featured Moe Betta; the second, Grynch and Afrok. With The Seshen, Gems. Nectar Lounge, 412 N. 36th St., 632-2020, nectarlounge.com. 8 p.m. $7 adv./$10 DOS. MICHAEL F. BERRY